You’ve probably been to many events with one, but to the common eye, what a sound board does can be pretty ambiguous. This article will shed light on its functionality, components, and importance when handling live event sound.
WHAT IT DOES
Simply put, a sound board (also known as a mixing board or mixer) takes multiple input signals—such as microphones, instruments, iPods, DJ turntables, etc.—and merges them together so they can be sent to speakers as one signal.
An audio engineer's job is to ensure each input channel blends harmoniously to produce a well-balanced sound. They use a sound board to optimize the combined sounds by adjusting input levels, applying effects, equalization and dynamic processing.
Inputs: These are jacks/plug-ins where all the sound sources plug into. Audio signals typically enter the board through an XLR, 1/4" TRS, or RCA jack - the most common/standard audio inputs.
Channel EQ's: Every input sound source corresponds to a channel, and each channel typically has EQ potentiometers. These allow an audio engineer to control the sound source's frequency balance individually.
Auxiliary Channels: Commonly referred to as “aux channels,” these enable you to send a duplicate feed of a channel/input signal to additional devices. The aux channels output the duplicate feeds via a jack on the top or back of the sound board. The most common use of for these are during performances; a band member may want to hear the audio back with certain elements adjusted to their preference through their own dedicated monitor wedge or IEM (in-ear monitors).
Faders: These are the sliders on a sound board that enable an engineer to adjust the volume/presence of each channel within the final output or mix. All channels should start at 0dB (referred to as unity) and be adjusted accordingly from there. This is why an experienced audio engineer running the board is key, as their ears are trained to recognize precisely what is needed to create a quality listening experience.
Hopefully this article has provided some insight into the function of a sound board and its importance in live audio. The next time you attend an event with a speakers setup—from your cousin’s wedding to your favorite club—you’ll know that the whole production is (hopefully) being run through a sound board.